Seeking feedback. The render only took 4 days, 1.5 hours. The (plain) scene is
derived from the Photons_Radiosity.pov, with my own shape used - a sphere with
200 numbered equal sized circular flat faces. The left is quite reflective and
gives me pause to reconsider if a mirrorball can be adequately created in
POVRAY.
The right... I'd like to have one of those (in glass or plastic or whatever).

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Preview of image 'dcc_photons_radiosity.jpg'

Graham wrote:

> Seeking feedback. The render only took 4 days, 1.5 hours.

Looks nice. Did you test without engraved numbers for comparison?

> The left is quite reflective and gives me pause to reconsider if
 > a mirrorball can be adequately created in POVRAY.

Actually that was one of the first things I tried with povray
when I discovered it about 3 years ago (see attachment, please
ignore the horribly disfigured blob humanoids).

If you expect to see strong photons from a mirrorball reflection
then the light which shines on the mirrorball must be a lot brighter
than the normal illumination of the target surface. This is so in
real life as well: hold such a thing into direct sunlight an you will
see a lot of spots anywhere the lighting is otherwise indirect. Or
shoot at it with a spotlight in an otherwise dark room.

But my mirror ball wasn't very sophisticated:

   sphere {0, 0.2 texture{T_Chrome_1E} normal {facets size 0.15}}

;)

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Preview of image 'disco.jpg'

> Seeking feedback. The render only took 4 days, 1.5 hours. The (plain) scene is
> derived from the Photons_Radiosity.pov, with my own shape used - a sphere with
> 200 numbered equal sized circular flat faces. The left is quite reflective and
> gives me pause to reconsider if a mirrorball can be adequately created in
> POVRAY.
> The right... I'd like to have one of those (in glass or plastic or whatever).
> 
> 
> 
> 
> ------------------------------------------------------------------------
> 

You obviously have poor bounding. The bounding boxes for the sphere, all 
200 facets and all 200 numbers are all pilled up and inflated to that of 
the sphere. Each ray must be tested against each and every litle component.
Try without the numbers, or use bump_maps for them. It should be much 
faster.
Considering the size of the numbers, faking it should be good enough.

The text object is relatively slow. Diferencing it from some object is 
slower. Multiply that slowdown by 200, add photons, transparency, 
reflection and dispersion, it's a perfect recipie for insane rendering 
times.


Alain

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Christian Froeschlin <chr### [at] chrfrde> wrote:
> Looks nice. Did you test without engraved numbers for comparison?
No, though I have done some since, but only as an exercise. The numbers
are the point of the original object. That said, the quality of the
reflections (and having read somewhere that disco-mirrorballs were
problematic in POVRay), I thought I'd enquire.

> Actually that was one of the first things I tried with povray
> when I discovered it about 3 years ago (see attachment, please
> ignore the horribly disfigured blob humanoids).
I will ignore them, except to say that this is a far better outcome
than I had with any of my first few povray pictures. Well done.

> But my mirror ball wasn't very sophisticated:
>    sphere {0, 0.2 texture{T_Chrome_1E} normal {facets size 0.15}}
> ;)
What you call not very sophisticated, I call elegant simplicity.
You don't want to know how many lines of looping code it took to
construct the basic shape, but I was looking to ensure opposite
faces were parallel and similar (amongst other things). This is
an example of my faceted shape:
http://news.povray.org/povray.binaries.animations/attachment/%3Cweb.4aecbfbe666e6f685e444af40%40news.povray.org%3E/hr48
0x360.gif

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Alain <aze### [at] qwertyorg> wrote:
> You obviously have poor bounding. The bounding boxes for the sphere, all
> 200 facets and all 200 numbers are all pilled up and inflated to that of
> the sphere. Each ray must be tested against each and every litle component.
> Try without the numbers, or use bump_maps for them. It should be much
> faster.
> Considering the size of the numbers, faking it should be good enough.
>
> The text object is relatively slow. Diferencing it from some object is
> slower. Multiply that slowdown by 200, add photons, transparency,
> reflection and dispersion, it's a perfect recipie for insane rendering
> times.

Okay, I asked for feedback - I appreciate your taking the time to respond
Alain. I read the reference material. I was aware that text objects are
slow to render. The numbers are integral to my concept of the object,
even though they don't add much to this picture, which I saw as an
opportunity to assess how it might appear in that setting. In a simple
and more 'realistic' setting it might appear like this:
http://i34.tinypic.com/2ldvwqv.jpg
Of course, this is just one frame from an animation, but you see...

I'm happy to have insane rendering times if it gives me (or gets me
closer to) what I want.

As for the poor bounding, the object (a sphere with bits removed) is
bounded by a sphere of exactly the same size and location. Please
enlighten me as to how it could be better bounded?

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Graham wrote:

> The numbers are integral to my concept of the object

Urgh ... do I smell a saving throw against a level 153 monster?

;)

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> Alain <aze### [at] qwertyorg> wrote:
>> You obviously have poor bounding. The bounding boxes for the sphere, all
>> 200 facets and all 200 numbers are all pilled up and inflated to that of
>> the sphere. Each ray must be tested against each and every litle component.
>> Try without the numbers, or use bump_maps for them. It should be much
>> faster.
>> Considering the size of the numbers, faking it should be good enough.
>>
>> The text object is relatively slow. Diferencing it from some object is
>> slower. Multiply that slowdown by 200, add photons, transparency,
>> reflection and dispersion, it's a perfect recipie for insane rendering
>> times.
> 
> Okay, I asked for feedback - I appreciate your taking the time to respond
> Alain. I read the reference material. I was aware that text objects are
> slow to render. The numbers are integral to my concept of the object,
> even though they don't add much to this picture, which I saw as an
> opportunity to assess how it might appear in that setting. In a simple
> and more 'realistic' setting it might appear like this:
> http://i34.tinypic.com/2ldvwqv.jpg
> Of course, this is just one frame from an animation, but you see...
I'd use an image pattern made after your numbers, and a bump map derived 
from the image pattern.
> 
> I'm happy to have insane rendering times if it gives me (or gets me
> closer to) what I want.
> 
> As for the poor bounding, the object (a sphere with bits removed) is
> bounded by a sphere of exactly the same size and location. Please
> enlighten me as to how it could be better bounded?
> 

To get beter bounding, you need to chop the sphere into many smaller 
parts and reassemble the sphere from those parts. A single part may 
consist of only a single facet, it's number and a bit of the surrounding 
spherical shape.
This will work as long as the object remains opaque. If the object is 
transparent, you'll see all the extra faces unless you use a merge, and 
then, the bounding problem returns.

Another way, would be to create a mesh equivalent of the faces and the 
numbers relief, make sure that it have an inside vector defined, and 
difference that mesh from the sphere.
If you go the mesh way, you may as well model the whole thing as a 
single mesh.


Alain

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Christian Froeschlin <chr### [at] chrfrde> wrote:
> Urgh ... do I smell a saving throw against a level 153 monster?
> ;)

Gaming of one description or another, or maybe a part of a trophy
for same - hence wanting to see how it looked in metal and glass.

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